class Shape {
    public void draw() {
        System.out.println("画形状");
    }
}
class Rectangle extends Shape {
    @Override
    public void draw() {
        System.out.println("画矩形");
    }
}
class Circle extends Shape {
    @Override
    public void draw() {
        System.out.println("画圆形");
    }
}
class Square extends Rectangle {
    @Override
    public void draw() {
        System.out.println("画正方形");
    }
}
public class work07 {
    public static void main(String[] args) {
        Shape shape = new Square();
        shape.draw();
    }
}
